Alarm and annunciator system



May 24, 1955 R. J. MARMORSTONE {M9259 ALARM AND ANNUNCIATOR SYSTEM FiledNov. 14, 1952 2 Sheets-fiheet 2 IN V EN TOR.

Emblem-'2 LMHPiIgPE 012E ff? 1 lflfpm's United States Patent 0 ALARM ANDANNUNCIATOR SYSTEM Robert J. Marmorstone, Chicago, 11]., assignor, bymesne assignments, to Panellit, Inc., Skokie, 11L, a corporation ofIllinois Application November 14, 1952, Serial No. 320,549

6 Claims. ((31. 340-213) This invention relates to electric alarmsystems for power plants, chemical process plants and other plantswherein protection is required for a great number of machines or processelements such as electric circuit breakers, machine bearings, fluidtreatment tanks and the like.

Large amounts of electric energy have been consumed I in earlier alarmsystems of this type. This was so mainly when the system used, for eachapparatus to be protected, a versatile relay unit comprising a pluralityof relay coils energized in different cycles to announce differentconditions such as alert, acknowledged alarm, return to normal, testingof annunciators, etc. Such consumption of electric energy is sometimes acause for complaint because of its cost; and more seriously, it mayimpair the safety of an alarm system, when the system utilizes directcurrent from a storage battery, as is usual for instance in powerplants.

Therefore it is a primary object of this invention to provide a lowdrain, high versatility alarm system for plants of the type mentioned.

A further important object is to provide an inexpensive relay unit forsuch a system. More particularly, it is an object to effect the requiredvariations of the control program with a minimum of relay coils andrelay switches in each relay unit. Another pertinent object is tostandardize the arrangement of such coils and switches so that basicelements, applicable in various alarm systems, can be used in systems ofthe present type.

These objects have been achieved by means of a circuit system whichcomprises, in addition to the basically required positive and negativebusses, at least two auxiliary bus wires, one of which carries electriccurrent from any of the relay units to an audible annunciator, while theother provides a normally open circuit for the control of each relayunit, as will be explained hereinafter.

Still other auxiliary busses may form a part of the new and improvedsystem, for the purpose of providing a sequence of flashing and steadyilluminations in an alarm lamp associated with each relay unit and forthe further pprpose of testing such alarm lamps, or sometimes for thepurpose of cutting a variety of alarm lamps into and out of the alarmprogram, during difierent phases thereof.

A most important feature of the new, improved relay unit is that itprovides two relay coils selectively energizable through a continuitytransfer switch system of the make-before-break type. it is by means ofthis switch system, in combination with more conventional alarmelements, that versatile low drain operation is allowed in a simple andeconomical manner.

The description of two preferred embodiments of the new circuit, whichfollows, Will specify certain details, and further details will beilustrated in the drawing appended hereto. Considerable variations arepossible as to such details, within the scope of this invention. Thisscope will be defined in the claims set forth at the end of thisspecification.

23%,259 Patented May 24, 1955 In the drawing:

Figure 1 is a schematic wiring diagram of a first em bodiment of thisinvention.

Figure 2 is a similar diagram of a second embodiment, modified as to thevisual annunciators.

Referring first to Figure 1:

The alarm system comprises a plurality of signal contacts or fieldswitches, one of which is shown at 11. Each signal contact is normallyopen for low-drain operation, and is closed under predeterminedconditions by well known thermostatic means, liquid level, flow orpressure responsive means, or equivalent apparatus (not shown). Thealarm system, when excited by and from any one signal contact 11, isexpected to cause a common, plantwide annunciator unit, such as a stronghorn 12, to operate and thereby to alert practically the entire plantpersonnel to the existing danger condition. it is further expectedsimultaneously to energize an alarm light. unit 24, associated with thecontact 11 and installed in a central control room. This serves toindicate the exact source of trouble.

In the system of Figure 1 the light unit 24 is advantageouslyconstructed in form of a so-called back-lighted name plate, suitablyimprinted to identify the circuit breaker, machine, tank or otherprocess unit associated with the corresponding switch 11. While only twoswitch and lamp arrangements 11, 24 are shown, a typical alarm system inaccordance herewith usually comprises several dozens, hundreds orsometimes thousands of such arrangements.

At a suitable location, usually in the central control room, apush-button 15 is provided, to enable the control room operator orsuperintendent to acknowledge the alerting signal sounded by the horn,that is, to silence the horn and thereby to eliminate unnecessarydisturbance of plant personnel, while still preserving a visual alarm inthe control room to identify the location of the acknowledged but as yetunremedied trouble. it is also desirable, in a versatile system, todistinguish this acknowledged visual alarm from the original alertingvisual alarm. For this purpose the push-button 15 and associatedcontrols according to the present system are expected to modify theenergization of the lamp 24. When normal conditions are re-establishedin the field, the signal contact 11 returns to normal position and thelamps 24 are advantageously de-energized, in the interest of low-drainoperation.

This program of alarm operations, which is known by itself, is hereachieved with particular economy, both as to first cost and operatingcost. At the same time the new system insures a particularly high degreeof safety, which is a feature of prime importance for an alarm system,

The system comprises an electric storage battery with a positiveterminal P and a negative terminal N. The horn 12 and the various lampunits 24 are energized by currents from P to N; and these currents arecontrolled by relay units 17, one of which is associated with eachsignal contact 11 and corresponding lamp unit 24. In the form of Figure1 the relay units 17 cooperate further with a flasher relay 1"7-F whichis provided in parallel with the horn 12 and in common with the entireset of relay units 17.

A first auxiliary bus wire R, common to all relay units 1"], has thehorn 12 interposed thereon; the other terminal of the horn beingconnected with the negative terminal N. A branch R of the R bus has aflasher motor 1i7-M interposed thereon, within the flasher relay l'i-F;the other terminal of the flasher motor being connected with thenegative bus N. In this manner, simultaneous operation of the horn andflasher motor is achieved.

A second auxiliary bus or control wire C is provided, common to allrelay units 17. interposed on this bus C is a normally openacknowledgment switch, operable by the acki wlcdgment push-button 15.The other terminal of this push-button switch is connected with thenegative bus N. Thus the bus wire C is normally de-energizcd but capableof being momentarily energized by depression of the ac ior-Jledgmcntpush-button if when wire C is connected with the positive bus l" throughsuitable switch and load arrangements in any one of the relay units 17;This control arrangement is important for the achievement of economicallow drain operation, as will be described presently.

At this point however, it may first be noted that there is also provideda third auxiliary bus F, having interposed thereon a flasher switch 17-3in the flasher relay 174?, the other side of the switch 17S beingconnected with the negative terminal N.

Still further there is provided a test bus T connected to the negativeterminal N through a normally open test push-button Each relay unit It?contains two relay coils, shown. at A and B respectively. One terminalof each coil A, E is connected to one battery terminal or line P, eitherthrough the signal Contact 11 or through a normally open seal-in switchAi, controlled by the A coil. The opposite side of each coil A, B isconnected to the other bat tery terminal or line N, through a continuitytransfer switch Bll, B-2 of the makobefore-break type, controlled by theB coil; one coil A being so connected through the normally closed partB-ll of this switch, while the other coil B is so connected through thenormally open part B2 or" this switch. Additionally a normally openswitch A-2, controlled by the A-coil, is connected on the one handbetween the B coil and the switch l3-2 and on the other hand to the Cbus.

The remaining circuitry is rather simple. A normally open switch A3controlled by the A coil is provided in each relay unit It? and isconnected between the P and R busses, in order to energize the horn i2and flasher motor 17-M at the proper time. A system of double throwswitches Ad, A4 and B3, 3-4 is provided in each relay unit 17 for thecontrol of the lamp unit 24. One terminal of this lamp unit is connectedto the P bus; the other terminal of the lamp unit 24 is connected to thecommon terminal of the double throw switch A-4, A--5 controlled by the Acoil. The norinall opcn part A-4 of this double throw switch isconnected with the F bus leading to the flasher switch 17-5. Thenormally closed part A-5 of said double throw switch is connected withthe common terminal of the second double throw switch B-3, B4controlled. by the E coil. The normally open part B-4 of that switch isconnected with the negative terminal N while the normally closed part8-3 is connected to the test bus T.

In operation, so long as all signal contacts 11 are in their normal openposition, all circuits of the entire system are dead and all, loaddevices tie-energized, thereby safeguarding zero drain. of electricenergy from the battery through the external circuit system.

Upon the occurrence of abnormal conditions in the actuating apparatus ofany one signal contact 11 that contact closes, at least momentarily,thereby energizing the corresponding A coil through the normally closedpart B4; of the continuity transfer device B1, B-2. The energization ofthe coil A through the signal contact 11 may be only momentary,depending upon the operation of the actuating apparatus, but the coil Aimmediately seals in through the seal-in switch A-l. As a result, the Acoil cannot be (ls-energized except by subsequent opening of thecontinuity transfer switch element 13-1.

The energization and scaling in of the A coil closes the normally openswitch A-3, thereby establishing a circuit from the positive terminal Pthrough A-3 and R and the born 12 to the negative terminal N. The horn12 begins to sound. Simultaneously a circuit is also made from thepositive terminal P through A--3, R, R, 17-M to N, starting the flashermotor. Still another circuit is made from the positive terminal Pthrough the lamp unit 24, switch element A-4, bus F and flasher switch17S to the negative terminal N. Flashing of the signal lamps 24- starts,simul-taneously with the sounding of the horn.

Up to this time the second relay coil B was de-energized. Now, when thecontrol room operator hears the horn and when he has noted the source ofthe trouble by inspection of the series of lamp units 24, he willnormally depress the acknowledgment push-button T5 for a moment. Thisestablishes a momentary circuit from the positive terminal P through thesignal contact 11 and/or seal-in switch. A-l and further through thecoil. B, switch A,2 (closed by coil A), control bus C and momentarilyclosed switch 15 to the negative terminal N. This energizes the coil 13and thereby operates the make-beforebreak continuity transfer switch 34,2-4., with the following effect:

Momentarily both B-1 and B4; are closed; so that the energization of theE coil occurs both through the switch l3-2 and the switch A-Z, thelatter still being closed by the coil A. it can thus be said that thecircuit system comprising the coils A, B and switches B4, 13-2 and A-2constitutes a seal-in before seal-out arrangement for the coils B and Arespectively. During a very short interval upon the depression of theacknowledgment push-button 1-5 both coils A and B are energized;immediately thereafter coil A is de-energized and only B is energized.

Expressed otherwise: momentary triggering of the B coil, sufficient forseal-in thereof at B2, is obtained by the switches 15 and A-2. It isfollowed rather than preceded or paralleled by the sealing out of the Acoil at 13-1, by means of the known make-before-break construction ofthe switch 5-1, 3-2.

For the alarm program the energization of the B coil and de-energizationof the A coil has the effect that the switch A3 is opened, silencing thehorn and stopping the flasher; the switch A-4, A-S is reversed,connecting the lamps to the switch B-3, B4 instead of the F bus; and theswitch B3, B-4 is reversed, connecting the lamps 24 between the P and Nbusses. Flashing of the lamps terminates and is followed by a steadybright illumination.

In the foregoing description it has been assumed that the signal contact11 is and remains in closed condition at the time when theacknowledgment push-button 15 is depressed. The energization of the Bcoil is then effected and maintained through the signal contact 11. Itcould not be maintained through the seal-in switch A-l, which opens whencoil A is de-energizcd.

Assuming, on the other hand, that the signal contact 11 is open when theacknowledgment push-button 15 is depressed, the effect is that bothcoils A and B are (lo-energized; that is, a normal condition isrte-established. if the open condition of the signal contact 11 is dueonly to fluctuations of the controlling apparatus and if accordingly thesignal contact 11 closes again after a short time, a new alarm isstarted; resulting in renewed sounding of the horn and flashing of thelamp unit.

Usually however there is no such resetting to normal condition bydepressing of the acknowledgment pushbutton, and no such restarting ofthe alarm, since the signal contact 11, as mentioned, is likely to be inclosed, condition by the time that the alert signal is acknowledged.

Likewise it is possible and desirable in many instances tore-establishnormal conditions of the system automatically by' the, reopening of thesignal contact 11, and the present system provides for this purpose. Thereopening of the signal contact tie-energizes the B coil,

thereby reversing the switches B-l, B-2 and B-3, B-4 again.

At this time the reversal of the switches B-1 and B-2, regardless ofsequence thereof, has no efiect, both switches 11 and'A-l being open.

On the other hand the reversal of the switch B3, B-4 breaks the circuitfrom the positive terminal P- through the lamp units24, closed switchA-5 and switch 13-4 to the negative terminal N, thereby extinguishingthe lamps. The lamps are now connected to the test bus T through thenormally closed switch B-3, for occasional testing by the push-button16.

The modified system of Figure 2 utilizes, as may be noted from thedrawing, the same seal-in before seal-out arrangement A, B, B-l, B-2,A-2 as has been described above. It also energizes the born 12 throughthe same bus R as has been explained. The system is modified howeverwith respect to the lamp unit.

The back-lighted name plate and flasher arrangement as described aboveis preferable mainly in two instances: (1) in central control roomswhere there is a great multiplicity of alarms in a relatively smallspace and where the attendant must read some definite legend in order tointerpret the appearance of an alarm light properly, and (2) in graphicpanels where a lettered name plate forms an integral part of a flowdiagram symbol and where the use of more than one lamp unit, for therepresentation of one field apparatus, would be confusing. On the otherhand, a combination of two or more bullseye light elements has theadvantage of compactness coupled with excellent visibility over a widerange of distances and viewing angles. Whenever such considerations arecontrolling the system of Figure 2 will be found preferable.

This system uses the same buses P, R, C, T and N as described above. Itfurther uses relay units 17' comprising the same seal-in before seal-outsystem and bus R energization system as described above. There may beused a red signal lamp 24' of the bullseye type, connected in much thesame manner as is the lamp 24 described above, except that the switchA-4 is connected to the lamp on the one hand and to the negativeterminal N on the other. Usually it is then desirable to add a whitesignal lamp 24A of the bullseye type, connected on the one hand to thepositive terminal P and on the other to the common terminal of a doublethrow switch A-6, A-7, the normally open part of this switch, A-6, beingconnected to the negative terminal N and the normally closed part A-7 tothe test bus T.

As a result, both signal lamps are off during normal conditions. Bothare on during the alert. The red lamp alone is on during theacknowledged alarm. Both lamps are on during a 'test. The operation ofthe horn is the same as before.

A system according to Figure l, equipped with all of the bus wiresshown, may have diiferent annunciator and relay systems connectedthereto. Some of these annunciator and relay systems may be those shownin Figure 1 while others may be those shown in Figure 2. There will beno mutual interference or feed-back.

Still further modifications no doubt will occur to persons skilled inthe art upon a study of this disclosure.

I claim:

1. In an alarm system for the protection of a series of devices, acorresponding series of signal switches; a corresponding series of alarmrelay units; at least one annunciator specially associated with eachunit; a common annunciator associated with the entire series of units; anormally open acknowledgment switch common to all of said units; a pairof energizing voltage terminals associated with the entire series ofunit; each unit comprising: a make-before-break type switch, a firstrelay coil and a second relay coil; one terminal of each of said coilsbeing connected to one of said terminals through the correspondingsignal switch, the other terminal of the first coil being connected tothe other energizing voltage terminal through the normally closed partof the make-beforebreak type switch, the second coil controlling saidmakebefore-break type switch, and the other terminal of the second coilbeing connected to said other energizing voltage terminal through thenormally open part of the makebefore-break type switch and in paralleltherewith, through a normally open switch and said acknowledgment switchin series therewith, said latter normally open switch being controlledby the first coil; switch means in each unit controlled by said relaycoils for de-energizing the specially associated annunciator when theacknowledgment switch has been closed and the associated signal switchis open, to produce a first announcement of the common annunciator andrespective specially associated annunciator, by a change in the state ofenergization of the respective first cd ils, when the respective signalswitches close, and to produce a different announcement of therespective specially associated annunciators while stopping said firstannouncement of the common annunciator upon operation of saidacknowledgment switch.

2. An alarm system as described in claim 1 wherein both coils of eachrelay unit have their first mentioned terminals connected to said oneenergizing Voltage terminal through two switches in parallel, one ofsaid parallel switches being said associated signal switch and the otherbeing automatically actuated by the associated first coil.

3. An alarm system as described in claim 1 wherein said switch means ofeach unit comprises, in circuit with the respective annunciator, firstrelay coil annunciator control contacts in two branch circuits leadingto one of said energizing voltage terminals, said branch circuitsincluding means to produce different operations of the respectiveannunciators, means for rendering said respective branch circuitsoperative respectively before and after operation of the acknowledgmentswitch.

4. An alarm system as described in claim 3 wherein at least some of saidspecially associated annunciators are lamps, a flasher switch connectedin common with one of said two branch circuits of each annunciator unit,said first relay coil contacts in one of said branches of eachannunciator unit being normally closed contacts and the first relay coilcontacts in the other associated branch circuit being normally openedcontacts, means connecting each of said lamps to said energizing voltageterminals through a series circuit of said normally opened first relaycoil contacts in said associated one branch and said flasher typeswitch, and said other associated branch shunting said flasher typeswitch and connecting the associated lamp to said energizing voltageterminals through a series circuit of normally closed first relay coilcontacts and normally open second relay coil contacts.

5. An alarm system as described in claim 3 wherein the speciallyassociated annunciator in each unit comprises a pair of lamps, one ofsaid lamps being in one of said associated branch circuits and the otherlamp being in the other of said associated branch circuits, said firstrelay coil contacts in one of said branches being normally closed, saidfirst relay coil contacts in the other branch circuit being normallyopened to energize the alarm lamp when an abnormal condition exists,normally open contacts of said second relay coil connecting the normallyclosed first relay coil contacts in said one branch circuit to saidenergizing voltage terminals, so that the alarm light in that branchcircuit is energized when the first coil is in its normal position andthe second coil is in its.

abnormal position, additional normally open contacts of said first relaycoil shunting said normally closed first relay coil contacts and saidnormally open second relay coil contacts in said one branch to energizethe alarm lamp therein when the first relay coil is in its abnormalposition.

6. A low drain alarm system comprising a pair of energizing voltageterminal, first and second normally de-energized branch circuitsconnected between said energizing voltage terminals, a first normallyde-energized relay coil in said first branch circuit and a secondnormally de-energized coil in the second branch circuit, a normally opencondition-responsive signal switch means connected in series with saidrelay coils of both branch circuits and adapted to close upon existenceof an abnormal condition, normally open contacts of said first relaycoil in series with said second relay coil in said second branch circuitand a normally opened acknowledgment switch in series with saidlast-mentioned normally opened contacts in said second branch circuitwhich i energize said second relay coil when said first relay coil isenergized and the normally open acknowledgment switch is momentarilyclosed, make-before-break switch contacts including normally closedcontacts in series with said first relay coil in said first branchcircuit for effecting energization of that coil upon closing of theassociated signal switch, and normally open contacts connected in shuntwith said normally open first relay contacts and said normally openacknowledgment switch of said. second branch circuit, said normally opencontacts of said mak'e-before-break contacts arranged to be closed uponenergization of said second relay and said normally closed contacts ofsaid pair arranged to open following closing of the last-mentionedmake-before-break contacts, means for providing a first signalannouncement responsive to the energization of said first relay coil,and means for providing a second signal announcement responsive to theenergization of said second relay coil.

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